Overview of Post Processing Framework

Overview

OpenMW supports a moddable post process framework for creating and controlling screenspace effects. This is integrated into OpenMW’s Lua API, see reference for details.

Basic concepts

Pass
Describes a single shader invocation pass. Currently only pixel (also known as fragment) shaders are supported.
Technique/Shader
An ordered list of passes, techniques will encompass a single effect like bloom or SSAO. Technique is interchangable with shader.

Installing and Activating

Shaders are managed through the virtual file system, simply install the associated archive or folder as described in mod-install. Shaders must be in the Shaders directory to be discoverable. A shader can be activated in one of two ways:

  1. Adding the shaders filename (without its extension) to the end of the chain list in settings.cfg.
  2. Using the in game post processor HUD, which can be activated with the F2 key by default. This is the recommended method as manual editing can be error prone.

Hot Reloading

It is possible to modify a shader without restarting OpenMW, live reload must be enabled in settings.cfg. Whenever a file is modified and saved, the shader will automatically reload in game. This allows shaders to be written in a text editor you are comfortable with. The only restriction is that new shaders cannot be added, as the VFS will not be rebuilt and OpenMW will not be aware of the new file.